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1.
本文研究随机多元回归模型的线性性检验.所提出的检验统计量是由两个统计量之和形成的.第一个是由最小二乘回归拟合的残差构造的,它具有渐近x2分布,但在完全对立假设检验时,它不是相容的.另一个则是基于对上述残差量的回归核估计,在零假设成立时,它趋于零,在对立假设成立时,则趋于无穷大.理论结果表明,本文的检验方法在完全对立假设下仍有相容性.模拟结果显示出,此方法在许多对立假设下,具有较好的功效.  相似文献   

2.
若f(x,y)在不动点为鞍点的特征值满足λ1>1>|λ2|>0,|λ1·λ2|<1,则f(x,y)限制在鞍点的局部有公式α=1+1nr是局部熵,α是局部分维数.把公式应用到Henon映射中,当α=1.4,b=0.3时,得到1nr=0.454,α=1.244.  相似文献   

3.
本文由过去提出的医学随访研究基础方法和应用模型设计出320个常用临床试验方案,制成设计供临床应用.与以往设计相比,其优点是1.便于限定失访水平,2.没有来自信息性终检的偏性,3.便于限定终末终检率在其阈值之下,避免设计错误,保证结果的可靠性,4.设计灵活,无Morgan误差.利用这些表可简化设计过程.附工作实例描述其使用方法.  相似文献   

4.
本文首先对方程(1.1)建立了Lyapunov函数,然后在P=0的情况下,证明了平庸解x=0在大范围内的渐近稳定性,和在p≠0的情况下,研究了(1.1)式的解的有界性问题.这些结论对一些众所周知的成果有所改进.  相似文献   

5.
在课堂教学中,教师要把握好学生的思维活动,激发学生的发现欲和创造欲.从而使他们在原有知识的基础上,有所发现,有所突破,有所创新.使学生的思维“空间”振奋起来,促进思维发展,在教学中将受到事半功倍的效果.  相似文献   

6.
Caflisch[1,2]在Euler方程存在光滑解的假设下,证明了Boltzmann方程存在一个解,且该解在平均自由程趋于零的极限下与Euler解一致.不幸的是Caflisch的证明有错误,其关键的引理6.1的结论太弱,不足以完成主要定理的证明.事实上,Caflisch在证明主要定理时,使用了比引理6.1更强的结论,但并未说明.本文改进了Caflisch的一个重要不等式;加强了原引理6.1的结论,并在修正了原主要定理证明过程中的其它错误后完成了它的证明.  相似文献   

7.
在古希腊,没有社会保险号码,没有电话号码,没有人口调查统计数字,没有选举后的投票数字,没有统计数据.当时,世界还没有数字化,但数字在希腊知识分子的头脑中至关重要.毕达哥拉斯的“万物皆数”的论断就证明了这一点.  相似文献   

8.
高阶非线性差分方程的振动性   总被引:3,自引:0,他引:3  
本文研究了差分方程△dx(n)+p(n)△(d-1)x(n)+H(n,x(n))=0,(1.1)△dx(n)+p(n)△(d-1)x(n,x(n))=Q(n).(1.2)在一定的条件下,证明了方程(1.1)与(1.2)在振动性方面的等价问题.对于方程(1.1)或(1.2),在n是偶数时的每一个有界解是振动的,在n是奇数时,每一个有界解是振动的或当→∞时单调趋于零的充要性定理也建立了.  相似文献   

9.
不等式问题千姿百态、五彩缤纷,其证明方法也不拘一格,妙招叠出.在我们所遇见的不等式中,时而有百思不得其解之经典题,时而为“问题中的等号取不到”而困惑、迷惘,更有“目标意识”不明朗而陷于山穷水尽时,…….当出现这些“症状”时,对我们学生而言,你不妨试用待定系数法,或许这一招能解你燃眉之急、还真够给力的.这不仅在数学学科的高考、竞赛中管用,而且在物理学中也占有一席之地.以下展示数例,权当抛砖引玉.  相似文献   

10.
本文中,我们给出了丢番图方程的解x,y,z,w的上界,其中p,q是给定的互素的正整数,a,b,c,d是给定的适合abed≠0的整数,此外,我们将指出在具体情形下如何把上界降低到方程允许的实际的解.最后,我们将用这个方法来解方程19.5x·17y=12.5z+41.17w+14, 5. 3x· 13y + 20= 7. 3z + 14. 13w和 13· 2x+ 5· 3y= 25. 2z+ 11. 3w.  相似文献   

11.
By using the link between the affine and the power norming, eight Hill estimators under power normalization for the tail index (the non-zero extreme value index) are suggested. Moreover, more compact and adaptive four Hill estimators under power normalization are derived based on the generalized Pareto distributions under power normalization. Two classes of harmonic t-Hill estimators under power normalization are also suggested. A comprehensive simulation study using the R-package shows that all the suggested estimators under power normalization work well, but in all cases the Hill estimators under power normalization based on Pareto distributions under power normalization are better. The two models under linear and power normalization for extreme value analysis are applied with comparison on a real data set of two pollutants, Sulphur Dioxide and Particulate Matter.  相似文献   

12.
The estimation problem in multivariate linear calibration with elliptical errors is considered under a loss function which can be derived from the Kullback-Leibler distance. First, we discuss the problem under normal errors and give unbiased estimate of risk of an alternative estimator by means of the Stein and Stein-Haff identities for multivariate normal distribution. From the unbiased estimate of risk, it is shown that a shrinkage estimator improves on the classical estimator under the loss function. Furthermore, from the extended Stein and Stein-Haff identities for our elliptically contoured distribution, the above result under normal errors is extended to the estimation problem under elliptical errors. We show that the shrinkage estimator obtained under normal models is better than the classical estimator under elliptical errors with the above loss function and hence we establish the robustness of the above shrinkage estimator.  相似文献   

13.
In this paper, we consider how to construct the optimal solutions for the undiscounted discrete time infinite horizon optimization problems. We present the conditions under which the limit of the solutions for the finite horizon problems is optimal among all attainable paths for the infinite horizon problem under two modified overtaking criteria, as well as the conditions under which it is the unique optimum under the sum-of-utilities criterion. The results are applied to a parametric example of a simple one-sector growth model to examine the impacts of discounting on the optimal path.  相似文献   

14.
We survey the main techniques for the construction of multivariate filter banks and present new results about special matrices of order four and eight suitable for their construction. Qiuhui Chen: Supported in part by NSFC under grant 10201034 and project-sponsored by SRF for ROCS, SEM. Charles A. Micchelli: Supported in part by the US National Science Foundation under grant CCR-0407476. Yuesheng Xu: All correspondence to this author. Supported in part by the US National Science Foundation under grant CCR-0407476, by the Natural Science Foundation of China under grant 10371122 and by the Chinese Academy of Sciences under the program “One Hundred Distinguished Chinese Young Scientists”.  相似文献   

15.
基于LMIs处理方法,研究了一类不确定线性切换系统在任意切换下的鲁棒控制问题.利用矩阵Schur补引理构造线性矩阵不等式,得到该系统的鲁棒稳定性的充要条件,同时也给出了在状态反馈下的鲁棒稳定性充要条件和在输出反馈下的充分条件.最后用数值例子对所得结果加以验证,说明了文中结果的正确性.  相似文献   

16.
In statistical parameter estimation problems, how well the parameters are estimated largely depends on the sampling design used. In the current paper, a modification of ranked set sampling(RSS) called moving extremes RSS(MERSS) is considered for the estimation of the scale and shape parameters for the log-logistic distribution. Several traditional estimators and ad hoc estimators will be studied under MERSS. The estimators under MERSS are compared to the corresponding ones under SRS. The simulation results show that the estimators under MERSS are significantly more efficient than the ones under SRS.  相似文献   

17.
We model strategic communication network formation with (i) link specificity: link maintenance lowers specific attention and thus value (negative externality previously ignored for communication) and (ii) value transferability via indirect links for informational but not for social value (positive externality modeled uniformly before). Assuming only social value, the pairwise stable set includes many nonstandard networks under high and particular combinations of complete components under low link specificity. Allowing for social and informational value reduces this set to certain fragmented networks under high and the complete network under low link specificity. These extremes are efficient, whereas intermediate link specificity generates inefficiency.  相似文献   

18.
基于经典博弈模型的Nash均衡点集的通有稳定性和具有不确定参数的n人非合作博弈均衡点的概念,探讨了具有不确定参数博弈的均衡点集的通有稳定性.参照Nash均衡点集稳定性的统一模式,构造了不确定博弈的问题空间和解空间,并证明了问题空间是一个完备度量空间,解映射是上半连续的,且解集是紧集(即usco(upper semicontinuous and compact-valued)映射),得到不确定参数博弈模型的解集通有稳定性的相关结论.  相似文献   

19.
An existence and uniqueness theorem for a class of stochastic delay differential equations is presented, and the convergence of Euler approximations for these equations is proved under general conditions. Moreover, the rate of almost sure convergence is obtained under local Lipschitz and also under monotonicity conditions.  相似文献   

20.
On multilevel iterative methods for optimization problems   总被引:2,自引:0,他引:2  
This paper is concerned with multilevel iterative methods which combine a descent scheme with a hierarchy of auxiliary problems in lower dimensional subspaces. The construction of auxiliary problems as well as applications to elasto-plastic model and linear programming are described. The auxiliary problem for the dual of a perturbed linear program is interpreted as a dual of perturbed aggregated linear program. Coercivity of the objective function over the feasible set is sufficient for the boundedness of the iterates. Equivalents of this condition are presented in special cases.Supported by NSF under grant DMS-8704169, AFOSR under grant 86-0126, and ONR under Contract N00014-83-K-0104. Consulting for American Airlines Decision Technologies, MD 2C55, P.O. Box 619616, DFW, TX 75261-9616, USA.Supported by NSF under grant DMS-8704169 and AFOSR under grant 86-0126.  相似文献   

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